The present invention relates to new derivatives of the antibiotics collectively defined as LL-F28249. These antibiotics preferably are produced by the fermentation of the microorganism Streptomyces cyaneogriseus subsp. noncyaneogenus, deposited in NRRL under deposit accession no. 15773. The LL-F28249 compounds and the method for their production are disclosed in European Patent Application Publication No. 170,006, incorporated herein by reference.
The present invention further relates to methods and compositions for preventing, treating or controlling helmintic, ectoparasitic, insect, acarid, and nematode infections and infestations in warm-blooded animals and agricultural crops by administering thereto prophylactically, therapeutically or pharmaceutically effective amount of the present .DELTA..sup.23 -LL-F28249 agents (compounds), mixtures thereof or the pharmaceutically and pharmacologically-acceptable salts thereof.
These infections not only cause devastating effects to animals but also seriously effect the economics of farmers in raising meat-producing animals such as swine, sheep, cattle, goats, rabbits and poultry. Further, such infections are a source of great concern for companion animals such as horses, dogs and cats. Therefore, effective methods for the treatment and prevention of these diseases constantly are being sought.